This invention relates to measurement devices and more particularly to a device for use in measuring water depth on the surface of a pathway, such as an airport runway or the like.
Easily ascertainable and accurate knowledge of the depth of water accumulating on the surface of an airport runway is very useful and in some situations a necessity. At airports, for example, decisions, during a rainstorm, as to which runways are safe to use and which are not, affect hundreds of lives. The ability of the airport operations manager to discern, at a glance, on which runways or portions thereof the danger of hydroplaning exists enables him to determine which runways to close and which to continue in use.
To be effective, a water depth measuring system must employ a sensing device which is easily installed at remote locations and which is capable of withstanding the constant passage of airplanes and vehicles. Further, the device must be capable of developing accurate information. In coassigned U.S. Pat. No. 3,882,381 and 3,873,927 sensors and a system are disclosed for reliably determining and indicating when water or ice are present on the surface of an airport runway or highway. However, these sensors and the systems of these patents were not intended for nor do they provide reliable water depth sensing and indication.